1G Looking for opinions on turboing an N/A 6-bolt 4g63

[Kaijcro]

I am currently swapping out the 4G37 for and N/A 6-bolt 4G63 I have a big 16 gauge turbo and didn’t realize until now that there have been some issues with turboing N/T 4G63’s and looking for some feedback and opinions, thanks!

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[19Eclipse90]

Issues begin to appear when you start trying to push power, generally with the piston ring lands. Also, if you utilize the non turbo transmission, the gears don't hold up well over time if attempting to run higher boost levels.

That said, my first car, a 1990 non turbo, is still in the family and was turbo swapped with the guts from a 1991 many years ago. The timing belt ended up snapping on that engine 3 or 4 years ago so, in order to get it back on the road again quickly, we threw the original non turbo engine back into it, with the non-turbo transmission. It is an otherwise stock car running wastegate pressure on a 14b and doesn't see any use outside of daily driver duties. I expect it will continue operating for many years to come.

So, personally, I would not suggest trying to push a 16G of any kind on an otherwise original non-turbo motor. If you are looking to make more than stock power or try to approach the limits of the 16G, definitely consider changing the pistons out. You didn't mention which transmission you intend to use but the same suggestion would follow depending on the goals for the car.

 

[Kaijcro]

Issues begin to appear when you start trying to push power, generally with the piston ring lands. Also, if you utilize the non turbo transmission, the gears don't hold up will over time if attempting to run higher boost levels.

That said, my first car, a 1990 non turbo, is still in the family and was turbo swapped with the guts from a 1991 many years ago. The timing belt ended up snapping on that my engine 3 or 4 years ago so, in order to get it back on the road again quickly, we threw the original non turbo engine back into it, with the non-turbo transmission. It is an otherwise stock car running wastegate pressure on a 14b and doesn't see any use outside of daily driver duties. I expect it will continue operating for many years to come.

So, personally, I would not suggest trying to push a 16G of any kind on an otherwise original non-turbo motor. If you are looking to make more than stock power or try to approach the limits of the 16G, definitely consider changing the pistons out. You didn't mention which transmission you intend to use but the same suggestion would follow depending on the goals for the car.

Thank you for the reply, I do have a GST transmission that I am going to run, I am a little too far into turbo charging the car with the 16g so I guess I will have to see what happens with that, I dont have very high goals when it comes to power I just thaught I might as well boost the car to make it a little more fun.

 

[pauleyman]

If those pics are recent motor is out of the car? You could change things now rather than later if time and budget allow.

 

[Kaijcro]

If those pics are recent motor is out of the car? You could change things now rather than later if time and budget allow.

I would 100% if I had the time my only issue is it will be my daily driver and I need the car by the end of may

 

[19Eclipse90]

Wastegate pressure with 9:1 compression pistons is still fun enough, don't get me wrong. It generally doesn't live up to the standards of most on here but it's definitely an improvement over an N/T.

Interestingly enough, that 1990 non turbo we have looked nearly exactly like yours when I got it, except it had a sunroof (and I wish it didn't).

 

[Kaijcro]

Wastegate pressure with 9:1 compression pistons is still fun enough, don't get me wrong. It generally doesn't live up to the standards of most on here but it's definitely an improvement over an N/T.

Interestingly enough, that 1990 non turbo we have looked nearly exactly like yours when I got it, except it had a sunroof.

That’s awesome man! I apreciate the feedback a lot I don’t have very high standards for this turbo and I’ll probobly only have 7-10 pounds of boost so I think she might hold up until the end or the summer

 

[biglady112]

This is all hearsay. A non turbo engine can go quite far in power production safely. Of course it is what they always say. It is all in the tune. I have personally done this on numerous cars in the 200-400whp range. Not a single one has ever damaged a piston from being “weak”. If you are not a bonehead they can take what you ask safely in the range without question.

Beyond that your mileage may very. Don’t be fooled, the motor will be just fine with a 16g.

 

[19Eclipse90]

It is all in the tune.

Quoted for truth.

Higher compression pistons are creating hotter cylinder temps and are more susceptible to knock. Without any other modification or changes, those non turbo pistons will be the weak point at increased boost levels.

Small enough world, @Kaijcro , if you have the itch to take it further, there's a nice resource in Colorado for you to get you boosting happily away - just look up @biglady112 !

 

[Kaijcro]

This is all hearsay. A non turbo engine can go quite far in power production safely. Of course it is what they always say. It is all in the tune. I have personally done this on numerous cars in the 200-400whp range. Not a single one has ever damaged a piston from being “weak”. If you are not a bonehead they can take what you ask safely in the range without question.

Beyond that your mileage may very. Don’t be fooled, the motor will be just fine with a 16g.

Thank you for the reply! Are you in CO I love to meet more people in the dsm committee near me

 

[biglady112]

Thank you for the reply! Are you in CO I love to meet more people in the dsm committee near me

I am in Denver. I have not owned a dsm in well over 10 years however. And I have not owned a 4g63 powered vehicle in almost 10 years. I just work on everyone else’s cars.

 

[Spleen8urLSX]

I know this thread is a little aged but came to shed some light on the topic for those who may stumble upon it in the future. As someone else said, tune is the biggest factor. The whole “wastegate pressure on a 14b is the limit!” myth from years ago is just that, a myth. As someone else mentioned the tune is the biggest factor and technology is light years beyond what it was 20 years ago when that myth was thought of. My car seen boost on the original non turbo 6 bolt engine for several years and about 20k miles. First a China 16g, then real evo3 16g, then an 8 blade hx35 in a .70ar open t3 housing, then last a Borg s363sxe in a .82ar open t3 housing.

First set up was the cheap China 16g, very basic. Ported 2g manifold, cheap tubular o2 housing, 3” exhaust, ported 1g intake manifold, 560cc injectors, aeromotive 340 pump, SAFC 2 controlling fuel. Made 283 at 24lbs on this set up. Drove it daily at times in the salt free months and beat the ever living crap out of it, typically 50 mile round trip commute to work 6-7 days a week. Unopened internally stock original non turbo 6 bolt. Biggest issue I found is I had to run 1 gallon of 110 octane race gas to every 4 gallons of 93 octane pump gas or else I’d see knock, with no way to control timing the timing in the stock turbo ecu was too aggressive for the 9:1 compression otherwise.

Then upgraded to an evo 3 16g, ecmlink v3 full, 1450cc injectors, FP race exhaust manifold, speed density, pulled the head and threw a fresh felpro composite gasket in it with ARP head studs and bc272 cams. Car made 420whp and 430wtq on this set up on e85 spiking 28lbs and falling off to 24lbs. Also put several miles on this set up and beat the absolute living hell out of it.

Last set up I switched to a Borg s363sxe with a Morrison large runner t3 manifold. Made 454 on 22lbs on straight 93 octane pump gas on this set up. At this point I was getting ignorant with it for fun and had every intention of trying to hit 600 on e85 but never got to that point. Pistons didn’t fail, actually they still look fantastic, however the seal on the oil filter split mid 130mph pull with my buddies wife’s 3 valve Mustang on Cosby juice. Wiped out a balance shaft bearing and the oil pump, otherwise had a lot of fight left.

The irony, not only does my new bottom end also have brand new non turbo pistons, but after several years of boost it will be its first time on a 14b (going a different direction with the rebuild). I even accidentally seen 45lbs (perhaps more, Omni 4 bar would’ve been maxed so could have been more) on the s363 and LUCKILY it just went completely lean and fell on it’s face but survived it no problem. I’d say after thousands of miles at far beyond the myth’d limit, we can chalk that up as just that. Take it as what you will and can’t say everyone would have the same result as there’s so many variables, but I wouldn’t hesitate to run a 16g on a stock non turbo bottom end in the least bit.